Two-stage jaw crusher



M y 1952 E. H. ANDERSON TWO-STAGE JAW CRUSHER 3 Sheets-Sheet 1 Filed Sept. 19, 1947 INVENTOR.

y 5, 1952 E. H. ANDERSON 2,595,219

TWO-STAGE JAW CRUSHER Filed Sept. 19, 1947 3 Sheets-Sheet 2 May 6, 1952 E. H. ANDERSON 2,595,219

TWO-STAGE JAW CRUSHER Filed Sept. 19, 1947 3 Sheets-Sheet 5 IN VEN TOR.

Patented May 6, 1 952 7 UNITED STATES PATENT OFFICE TWO-STAGE JAWCRUSHER Einar Hviid Anderson, J oliet, 111.

Application September 19, 1947, Serial No. 775,114

This invention relates to machines for crushing and sub-dividing hard material such as rock and particularly to a high capacity, jaw-type crusherada'pted to economically supply a twostage crushing operation.

- It is an object of my present invention to provide a compact and comparatively light crushing machine utlizing with high-efficiency, its source of power to effect a primary and secondary crushing operation through the reciprocation and gymtion of an upstanding jaw-carrying pitman mounted intermediately of two widely spaced jaw members and forming in conjunction therewith, primary and secondary crushing mechanism disposed in side by side relation.

Another object is the provision of an improved jaw-type crushing machine wherein through the relation of a horizontally disposed driving eccentric with an upstanding jaw-carrying pitman and a toggle connection at the upper end of said pitman, downward feeding of material and subsequent rapid and controlled discharge of the crushed or sub-divided material is very efiiciently obtained, in a primary crushing operation.

A further object is the provision of a high capacity; two-stage crushing machine wherein application of crushing power forv two crushing operations is effected substantially uniformly throughout the entire cycles of a driven eccentric, through the medium of a common jaw-carrying pitman opposed at one side to a primary crushing jaw and opposed on its opposite side to a secondary crushing jaw. I

It is another object to provide a compact, rela-.- tively light =two-stage crushing machine of-high capacitywhereln the center of gravity of the over-all machine is relatively low as contrasted with conventional jaw crushers now in extensive use and wherein the primary and secondary crushlngchambers are disposed in side by side relation rather than in superimposed relation to materially decrease the over-all weight and size of the machine. I

A further object is the-provision of an improved jaw-type crusher of the class described wherein, for the amount of power required, the capacity is substantially doubled, as contrasted with the old conventional types of jaw crushers; wherein in primary crushing operations, mini- -'mum agitation at the top of the crushing chamber and maximum agitation at the bottom thereof is obtained, with maximum assistance to flow of material.

' A-still further object is to provide an improved jaw crusher of high capacity but requiring less 6 Claims. (Cl. 241-140) eccentric throw on the part of a jaw-carrying pitman and requiring materially less consumptionof power for its operationthan any conventional jaw crushers (single-or dual'stage) W in use.

These and other objects will be more apparent from the following description made in conjunction with the accompanying drawings wherein like reference characters refer-to similar parts throu hout the several views and in which:

- Fig. 1 is a vertical section showing an embodiment of my improved two-stage crusher having incorporated therewith, a crushing rollattachment which electively may be utilized for producing quite fine particles; 7 Fig. 2 is a front elevation of the machine with the supply chutes detached; 4

Fig. 3 is a diagrammatical, vertical section showing the relationship of the pitman-carried jaws with the other jaws of the primary and secondary mechanism during four quadrant stages during the g ratory cycle of operation of the pitman; and e v Fig. 4 is a vertical section, taken longitudinally of a somewhat different embodiment of the invention. 1

In the drawings, Figures 1 to 3,. inclusive, a rock crusher unit forming a part of the complete screening and crushing plant is illustrated em bodying the principle of my invention Figures 1 and 2 of the drawings illustrate an auxiliary crusher roll unit cooperatively associated-with my main unit and which may be utilized in instances. where an aggregate or'particle size is desired, less than that usually requiredpyThe structure of my main unitis disposed aboveithe heavy broken line AA of Fig. l. 7

My main two-stage crushing unit is mounted in an upright frame comprising a pair of heavy spaced, yertical side plates 6 having out-turned attachment flanges 6a and 6b at their lower and upper edges and transversely inter-connected at their upper portions by a wide top or cover plate I at the forward end of the machine and, by other transverse tie members which have dual'funcltions, later to be described. These tie members include a pair of heavy channel members 9 and I0, traversing the lower rear portion of the frame and the lower front end of the frame, respectively and having the additional-function of retaining adjustable jaw-positioning mechanism to be later described in detail.

tical side plates 6 and as shown, being mounted for oscillatory adjustment on a heavy shaft 12, which extends through frame plate 6 and is journaled therein, preferably through the medium of bearings eccentrically mounted in frame plates 6 in the manner illustrated in my co-pending application, S. N. 678,438, to facilitate adjustment of the shaft l2 when the eccentric bearings are attached to the frame sides in various positions. Jaw H is provided with a heavy, cylindrical supporting bearing Ila at its upper end, journaled upon shaft [2 and the upper end of head Ila is enlarged to provide attachment means for a guide plate llb, declined from the rear upper edge of the machine frame inwardly to act as a guide or chute for larger material fed to theprimary crushing mechanism. The lower end of jaw ll is maintained in the desired, angled position with reference to the vertical, by suitable abutment means, as shown, in the form of a centrally weakened, transverse plate l3 interposed between a suitable grooved seat at the rear and lower end of jaw H and a horizontally adjustable wedge plate mechanism l4 slidably mounted in the adjustment-receiving channel 9. lhe wedge adjustmentmechanism may be similarto that disclosed in my said co-pending application, S. N. 678338, now abandoned (seeparticularly Fig. 4 thereof). Jaw II is provided in its face, with abutments and attachment means for detachably securing thereto, a primary crushing plate 15, which, as shown, is longitudinally ribbed from top to bottom and slightly convex in shape.

An adjustable, stationary, secondary crushing jawlfi is mounted in upstanding, transverse position within the forward portion of the frame and as shown, is of materially less height than that of primary jaw ll. Secondary jaw 16, at its upper end is provided with a heavy supporting sleeve or bearing [6a which is journaled for oscillation on a heavy, transverse shaft 17, traversing the side plates 6 of the frame and preferably'journaled in adjustable eccentric bearings (not shown) of the structure illustrated in my said co-pending application, S. N. 678,438. The lower end of secondary crushing jaw I6 is maintained in the desired, angled position, with reference 'to the vertical, by suitable adjustment means, as shown, in the form of a centrally weakened plate l8 interposed between a suitable grooved seat at the rear and lower end of jaw l6 and a horizontally adjustable wedge plate 19 of the identicalstructure of the wedge plate It for adjustment of the primary jaw ll. Jaw l6 has removably attached to .the upper edge thereof, a relatively wide, 'fiat material-guiding plate lBb whichis adapted to receive material delivered from the screening plant or other source, through a chute C, guiding that material to the top of the secondary crushing chamber. Jaw l6, like jaw H, is provided with suitable abutments and attachment means for detachably securing thereto, a secondary crushingplate 29 which is opposed to the primary crushing plate 15, but very widely spaced therefrom and maintained preferably at a higher level than the primary crushing plate.

An upstanding, dual action, jaw-carrying pitman 21 is mounted intermediately of the stationary, primary jaw H and the stationary, secondary jaw l6, having an enlarged, horizontal mounting sleeve 2m at its lower end which extends transversely between the side plates 6 of the frame and has mounted therein, a bearing fiq 11 iQP 'IWlQQ 749? F 9 93 3 c inde 2? 4 which is fixed to a heavy driven shaft 23jour-' naled in suitable bearings 24, detachably secured to the heavy side plates of the frame. Shaft 23 as shown, in Fig. 2, extends at each of its ends beyond bearings 24 and is provided with a pair of fly wheels 25.

With my improved construction, due to the relationship of the eccentric 22 with the primary and secondary jaws II and I6 respectively, and due to the toggle mounting of the upper end of upstanding pitman 21, only a relatively short throw of the driven eccentric is required, as contrasted with conventional jaw crushers now in wide use, thereby materially lessening wear of working parts and upon the crushing faces. I prefer to utilize an eccentric having an over-all throw of from three fourths to one inch as contrasted with over-all throws of one inch and a half now utilized. To obtain most eflicient results it is desirable to position the axis of shaft 23 some distance above the lower end of primary crushing plate 15 and a slight distance above the lower end of secondary crushing plate 20.

Pitman 2! extends upwardly a considerable distance beyondthe upper edges of both primary and secondary crushing plates 15 and 2B and has a fulcrum toggle connection between the front face thereof and the front or right hand and of the frame as viewed in Fig. l. The relationship of my improved toggle connection with the eccentric 22 and the stationary crushing faces 15 and 20 is important in the production of the peculiar gyratory movement produced upon the jawcarrying pitman and in the production of highly efiicient results. The said toggle connection includes a transversely disposed centrally weakenecl toggle plate 26 interposed between a channeled seat 27 fixed to the upper end and front face of pitman 2i and a channeled seat 28a formed in the outer wedge member of a wedgeadjustment mechanism 28 similar in structure to that previously described with reference to parts 14 and I9 and mounted within a heavy channel 29 transversely extending between and fixed to the side plates 6 of the frame. The free or upper end of pitman 2| is constantly urged towards the forward or right hand end of the frame and maintained in its rocking relationship and engagement with the seated edge of toggle 26 by suitable means such as a spring-actuated rod mecha nism comprising as shown a pair of connector rods 39 secured to the upper end of pitman 2: at their inner ends and extending horizontally and forwardly of the frame and passing through a heavy, upstanding abutment .plate 3|, in each 'instance and having in each instance, a heavy coil spring 32 surrounding the outer portion thereof and interposed between abutment plate 3| and a head or disc 33 adjustably affixed to the outer end of each rod 30 through adjustment and lock nuts 38a and 3012 respectively.

It will be noted that the upper end of pitman 2| as well as the entire toggle mechanism and its seats and adjustment mechanism as well as the rods 30 and their associated abutments and spring-receiving sockets, are entirely covered and protected by the transverse, wide top plate I of the frame.

The dual action, jaw-carrying pitman 2| is provided with suitable, inclined plate-attachment faces appropriately positioned and provided with supporting abutments for opposition to the primary and secondary crushing jaws II and IB respectively. A primary crushing plate 21p is detaghabi se ure t9. t 9 P tman 31 011- ing the products.

posing stationary, primary plate l5 and disposed in converging relationship thereto, from the top to the bottom of the crushing chamber formed between said crushing plates. The lower edge of crushing plate 2 lp terminates during the middle of the cycle of eccentric 22 along a line substantially in horizontal alignment with the lower edge of the stationary primary crushing plate |5. On the opposite or forward face of pitman 2| a relatively short, secondary crushing plate 2|s is detachably secured, opposing the stationary, secondary crushing plate 20 and converging from top to bottom, in its relationship therewith.

In considering the relationship between the cooperating primary and secondary crushing jaws of my improved construction, it is important to note that the pitman is gyrated through an endless, general elliptical path, the longer components of the path governing the up and down movements of the pitman rather than the transverse movements towards and away from the cooperating stationary jaws. This is eifected through the relationship of the toggle connection with the upper or free end of the pitman. In this connection, it will be noted that the fulcrum of the toggle 26 in its seat 2%, is disposed above the upper edges of both crushing faces 2|p and Us and the axis of the eccentric-carrying shaft 23 is disposed preferably slightly above the lower edges of the crushing jaws.

The structure described comprises a complete, two-stage crushing unit having the working parts thereof very compactly mounted and related, occupying little space and with the center of gravity thereof, disposed relatively low because of the pitman structure and its driving mechanism cooperating with the lower end of the pitman. Coarse material is fed into the primary crushing chamber between crushing plates l5 and 2 In and smaller material is delivered from chute C at the forward end of the machine over the inclined guide plate I61) and to the upper end of the secondary crushing chamber between jaw plates 20 and 2 Is.

My two-stage crushing unit is particularly adapted to be cooperatively associated with a compact roll crushing unit for further comminut- In Figs. 1 and 2, a crushing unit is illustrated, comprising relatively narrow, vertical side plates 35 having horizontal outturned attachment flanges 35% at the upper longitudinal edges thereof which are adapted to register with the base flanges 6a of my main unit and be rigidly secured thereto by suitable means such as the nutted bolts 36. The left hand ends of the side plates 6 of the main unit frame and of the sub frame 35 are longitudinally recessed.

to jointly provide a shaft-accommodatingslot 31 wherein a driven counter shaft 38 for the crusher roll unit, is disposed. Suitable bearings 39 are mounted on the outwardly projecting ends of a tie rail 40 transversely connecting the rear ends of the frame plates 35. An inner crushing roll 4| is mounted medially of the crusher. roll frame traversing the space between side plates 35 and fixed to a shaft 42 which is journaled in suitable bearings 42a which are mounted for horizontal limited sliding between the space plates 35, a heavy coil spring 43 being interposed between each of said bearings and a vertical abutment partition 44 disposed therebehind.

A second or outer crushing roll 45 is mounted in close spaced relation to roll 4| between frame sides 35 fixed to a driven shaft 46 which projects through the frame plates 35 and is journaled in.

bearings detachably secured to the outer sides of plates 35. The axes of shafts 42 and 46 lie in a common horizontal plane well below the discharge of the secondary crushing mechanism of my main ,unit, with the space below saidcrushing rolls being disposed to receive material discharged from said secondary crushingmechanism. The rolls 4| and 45 are driven inopposite directions as indicated by the arrows in Fig. 1, to assist in feeding material between the rolls, dropped between the upper portions thereof.

To assure positive feeding of such material, 7

I preferably provide a reciprocating, depending tamper bar 4'! removably secured to the lower endofthe pitman 2| of the main crusher unit and depending from the forward face thereof and directed to intermittently force material downwardly in the upper throat between the two crushing rolls due to. the up and down components during the gyration of pitman 2|. Tamper bar 41 is preferably constructed of a resilient material, such as rubber.

Operation The cycle of operation of my two-stage jaw crusher is well illustrated diagrammatically in Fig. 3. Driving of shaft 23 counter-clockwise as viewed in Figs. 1 and 3, through the action of eccentric cylinder 22 and the relationship of pitman 2| with the toggle plate 26, produces gyratory movement of the crushing faces 2 p and Us through endlessly curved, downwardly elongated elliptical paths. 1,

Referring to the cycle of operation in the primary crushing mechanism, the full line position of the crushing face 2 lp referred to in that view, by the numeral 1. The first cycle of operation from the full. line position, through a quarter revolution of shaft 23, causes the movable crushing face 2| p to move inwardly towards the stationary crushin face l5 and to simultaneously move upwardly, agitating material considerably in the upper portion of the crushing chamber, but producing little agitation at the lower end of the primary crushing chamber. The second position of the pitman and its jaws indicated by the numeral 2, illustrates the beginning of the second step of the cycle wherein the crushing plate Zip moves towards the stationary crushing plate l5 and simultaneously downward, carrying out the crushing operation and simultaneously forcing material asnit is being. crushed, downwardly for discharge. The dotted line position of thepitman and its jaws-indicated by the numeral 3 illustrates the beginningof the third cycle of operation which produces a further forced feed of the material downward with a retraction of the movable crushing plate 2|p. The dotted line position 4 in Fig: 3 indicates the beginning of the last cycle of operation where the material is quickly discharged as the movable crushing plate 2|p further retracts and simultaneously moves upward.

The cycle of operation in the secondary crushing chamber, it will be noted, indicates that the first cycle of operation produces an upward and retractive'movement of the secondary crushing face 2|s from the stationary face 2@; the second cycle produces a further retraction and downward component; the third cycle produces'a downward component of movement'of the crush ing face 2|s and a lesser movement of that'face towards the stationary jaw and the fourth cycle of operation produces a further retraction with s: smallupward component of movement of face Z-fs relative to the stationary, secondary jaw.

The eccentric actuation of the lower end of the pitman with the toggle relation at the upper end accentuates vibration in the upper portion of theprimary crushing chamber and lessens vibration in the lower or delivery portion of the primary crushing chamber, which is highly desir able. It further produces the maximum of forced feeding of materials in the primary crushin chamber and produces a feeding through one cycle of operation which is desirable in the secondary crushing chamber.

In Fig} 4, a somewhat different form of my invention is illustrated wherein the frame struc ture of the machine, the adjustable stationary aw H and general structure of the dual action pitman 2| and its mounting and driving through eccentric 22, is identical with the form first described. However, in this modified form, a driven crushing roll 50 is substituted for the secondary crushing jaw it of the form first described and is related with the secondary crushing face 51 of the pitman to receive and help guide smaller material into the secondary crushing chamber provided by face 5! and roll 50. In this connection, I prefer to provide the crushing plate 5! with a concave, recessed lower transverse portion 5m extending substantially concentric of roll 50 and spaced the requisite distance therefrom.

Crushing roll 50 is driven in the direction indicated by the arrow in Fig. 4, by suitable driving connections with the pitman shaft 23, not shown.

In both forms of the invention illustrated, it will be noted that power is utilized throughout the full cycle of operation of eccentric cylinder 22 for applying crushing pressure. In half of said cycle of operation, crushing power is applied to the primary crushing mechanism and in the other half of said cycle, this crushing power is applied to the secondary crushing mechanism. Thus, a substantially constant bearing load is produced, resulting in a minimum amount of bearing shock, as contrasted with the rather spasmodic action of conventional jaw crushers now utilized. With such application of power crushing force, relatively light fly wheels may be iitilized on the eccentric shaft 23, materially reduoing'the over-all weight and cost of material.

By reference to the diagrammatic viewv (Fig. 3) it-will be seen that the forced feeding or downward component of movement of the pitman in both primary and secondary crushing operations, is substantial, as contrasted with the horizontal or crushing and retracting components. This enables highly efficient results to be obtained with the use of an eccentric having a relatively short throw (three fourths of an inch total is recommended) By applying the eccentric action to the lower end of the pitman with the axis of the eccentric shaft disposed somewhat above the lower edges of the stationary jaws and by relating the toggle with the upper end of the pitman within the general scope herein set forth, highly efficient crushing and separation of primary and secondary jaws is obtained, with minimum vibration ortilting of the pitman-carried jaws near the discharge ends of the respective crushing mechanisms while in the primary crushing mechanism, considerable agitation and tilting action is obtained in the upper portions of that crushing chamber;

My crushing unit is adapted for quickadjustment to suit various conditions as to size and hardness of raw materials as well asto vary the size of the output as desired. In this connection,- it will be understood that through the adjustable eccentric mounting of the fixed jaw-supporting shafts l2 and H, the upper portions of said jaws may be adjusted horizontally and to some extent, vertically, with reference to the jaw-carrying pitman. The transverse wedge plate adjustments l4 and I9 permit the lower ends of said jaws II and [6 to be adjusted horizontally and further, permit variance in the angle of convergence of said jaws with the cooperating primary and secondary crushing plates Zip and 21s, of the gyrating pitman.

Fromthe foregoing description, it will be seen that I have provided a very compact, high capacity, crushing machine utilizingthe full cycle of rotary power for alternative crushing operations in primary and secondary crushing chambers and utilizing two faces of a bottom driven pitman to provide dual stage crushing.

It will further be seen that with my improved structure, the center of gravity of my machine is exceedingly low as contrasted with other jaw crushers; minimum wear is produced on power shafts, bearings and crushing faces with application of crushing pressure and downward material-feeding to best advantage.

t will of course, be understood that various changes may be made in the form, details, ar rangement and proportions of the parts without departing from the scope of my invention.

What I claim is:

1. A two-stage jaw type crusher having, in combination, a frame provided with upstanding spaced sides, an upstanding, normally fixed primary jaw and an upstanding, normally fixed secondary jaw, said secondary jaw being subs'tantially shorter than said primary jaw, said normally fixed jaws being mounted transversely in said frame and being spaced widely apart in opposed relation, an upstanding pitman mounted medially of said jaws and carrying on one face thereof a primary crushingjaw opposed to said normally fixed primary jaw in converging relationship thereto from top to bottom, said pitman carrying on its opposite face a secondary crushing jaw opposed to said normally fixed secondary jaw and converging in relation thereto from top to bottom, and being of generally the same height as said normally fixed secondary jaw,- a powerdriven eccentric journaled in the sides of said frame and extending transversely thereof and connected with the lower portion of said pitman for gyrating' the same, and a single toggle bar structure connecting the upper portion of the pitman above said secondary jaw with said frame,

whereby to provide a swinging fulcrum for the upper portion of said pitman, the cooperative functioning of said eccentric and said toggle bar being adapted to cause the primary jaw on said pitman to be gyrated through generally elliptical paths with a substantially long downward component of movement in the protraction of said pitman toward the normally fixed primary jaw, while the secondary jaw of the pitman is gy'i'ated through generally elliptical paths having a substantially long horizontal component of movement in the protraction of said pitmantoward said normally fixed secondary jaw.

2. A two-stage, jaw type crusher, having, in combination, a frame provided with upstanding s aced sides, an upstanding rimary jaw and a shorter upstanding secondary jaw, said jaws being mounted transversely within said frame and being spaced widely apart in opposed relation, an upstanding pitman mounted medially of said jaws and carrying on one face thereof a primary crushing jaw opposed to said first mentioned primary jaw in converging relation thereto from top to bottom, said pitman carrying on its opposite face a shorter secondary crushing jaw opposed to said first mentioned secondary jaw and converging in relation thereto from top to bottom, a power driven eccentric journaled in the sides of said frame and extending transversely thereof and connected with the lower portion of said pitman and revoluble on a horizontal axis for bodily gyrating said pitman, a toggle disposed transversely within said frame and connecting the upper portion of said pitman at a point above the upper edge of said secondary jaw with said frame to provide a swinging fulcrum for the upper portion of said pitman, fulcrum structure interposed between said frame and one edge of said toggle bar and compressiontension means for maintaining said fulcrum structure in predetermined operative relation to,

the upper end of said pitman.

3. A two-stage jaw type crusher having, in combination, a frame, a normally fixed primary jaw and a normally fixed secondary jaw mounted in said frame, said secondary jaw being substantially shorter than said primary jaw, said normally fixed jaws being spaced widely apart in opposed relation, an upstanding pitman mounted medially of said jaws and carrying on one face thereof a primary crushing jaw opposed to said normally fixed primary jaw, and carrying on its opposite face a secondary crushing jaw opposed to said normally fixed secondary jaw and being of generally the same height as said normally fixed secondary jaw, an eccentric connected with the lower portion of the pitman for gyrating the same, and a single compression-tension structure connecting the upper portion of the pitman with said frame at a point above the secondary jaw, whereby to provide a swinging fulcrum for the upper portion of the pitman ada ted to impart a differential movement to the primary and secondarv cr shing jaws on the pitman.

4. A two-stage jaw type crusher having, in combination, a frame, a normally fixed primary jaw and a normally fixed secondary jaw mounted in said frame, said secondary iaw being substantially shorter than said primary jaw, said normally fixed jaws being s aced widely apart in opposed relation, an upstanding pitman mounted medially of said jaws and carrying on one face thereof a primary crushing jaw opposed to said normally fixed primary jaw, and carrying on its opposite face a secondary crushing jaw opposed to said normally fixed secondary jaw and being of generally the same height as said normally fixed secondary jaw. an eccentric connected with the lower portion of the pitman for bodily gyrating the same, and an oscillating connection between the upper part of the pitman and the frame, said oscillating connection in cluding a structure in pivotal relation with the upper end of the pitman and adapted to oscillate in relation to the pitman along an axis intermediate the two crushing cavities formed by said opposed jaws, said structure being also in pivotal relation with the frame for oscillation along a normally fixed axis laterally removed from the upper end of the pitman, said axis being generally vertically aligned above the normally fixed secondary jaw, whereby to provide a swinging fulcrum for the upper portion of the pitman adapted to impart a differential movement to theprimary and secondary crushing jaws on the pitman.

5. A two-stage, jaw type crusher comprising a frame, an upstanding primary jaw and a' shorter, upstanding secondary jaw, said jaws being widely spaced apart in opposed relation, an upstanding pitman mounted -medially of said jaws and carrying on one face thereof a primary crushing jaw opposed to said first mentioned primary jaw in converging relationship thereto from top to bottom, said pitman carrying on its opposite face, a secondary crushing jaw opposed to said first mentioned secondary jaw and converging in relation thereto, from top to bottom, and being of generally the same height as said first mentioned secondary jaw, a toggle connection between the upper portion of said pitman and said frame, said toggle connection extending laterally from the upper portion of the pitman toward the first mentioned secondary jaw, said toggle being located at a level higher than the top of the secondary jaws, and power driven means for bodily gyrating said pitman through a downwardly elongated, generally elliptical path between said first mentioned pair of jaws, including an eccentric journalled in the crusher frame and means for rotating it about a center adjacent the lower edge of the secondary crushing jaw on the pitman, said primary jaw on the pitman including an upper portion extending upwardly above and a lower portion extending downwardly below the horizontal plane of the axis of said eccentric, said secondary jaw on the pitman extending substantially above said plane of the axis of said eccentric, and spring means adapted to maintain the pitman normally in operative position in relation to the toggle while permitting movement of the pitman about the eccentric in response to the presence of uncrushable material in the primary crushing cavity at a level below said plane of the axis of the eccentric or in the secondary crushing cavity at a level above said plane of the axis -of the cocentric.

6. A jaw type crusher having, in combination, a frame provided with upstanding spaced sides, an upstanding jaw-carrying pitman mounted between the sides of said frame and having a crushing plate fixed to one face thereof, a cooperating jaw normally fixed on said frame, opposed to said crushing plate and disposed in downwardly converging relation thereto, a horizontally disposed driven eccentric extending transversely between the sides of said frame and directly connected to the pitman at a level above the lower edge of the crushing plate but closer to the lower edge than to the upper edge of the crushing plate, the jaw on the pitman thus extending in part above and in part below the horizontal plane in which the axis of the eccentric lies, a toggle mechanism oscillably connected with the upper end of said pitman at a level close to the level of the upper edges of said crushing plate and jaw and oscillably connected to the base for oscillation about an axis laterally removed from the pitman and from the crushing cavity between plate and jaw and located at a level close to the level of the upper edges of said crushing plate and jaw, and spring means positioned and adapted to urge said pitman toward operative position against said toggle mechanism, said spring means being further adapted 11 to relieve pressure above a maximum between said jaws and to permit said pitman to rotate about the eccentric when unerushable material is postioned between the jaws at a level below the horizontal plane in which the axis of the eccentric lies.

HVBTD ANDERSGN.

Name Date u er Pagtz '-fr."r-f-.----7 Sept 15 Number Ngmber Name iDate Dodge a-, Got. 24, 1865 ue er 1- S nt. 22, 19 Kirksey May 12, 1914 Bakstadu-i-e Jan. 21, 1936 Wettlaufe: Nov. 2, 1937 Gruender 001;..4, 1938 Gruender Oct 2.4, 1939 FQREIGN BATE-B T Country Date France May 19, 19 83 Great Britain Sept. 13, 1938 

